1. Field of the Invention
This invention relates to systems and methods for fixation or immobilization and retraction of various anatomical and other structures during surgery, including, for example, surgical fixation and retraction of flesh, bone, feet, legs, arms, hands, digits, surgical drapes, and other surgical equipment.
2. Prior Art
Although elements of many new technologies have been transferred to medicine from their original fields, this has generally not happened in the area of basic surgical instruments, even though surgery still largely depends on the skill of an individual surgeon using these tools. Recent research and development activity in medical equipment has been more focused on expensive procedure sets, diagnostic tools, and life-support systems. As a result, conventional surgical fixation and retraction devices have changed slowly and suffer from a number of shortcomings.
(a) Retraction
Surgical retractors are used to provide medical personnel with the ability to hold open an incision area. Typically, retractors are band held or mount on a fixed support assembly. Restraining limbs and digits provides a particular challenge for medical personnel. Hand surgery requires a retraction system that provides a surgeon with flexibility and stability. For example, a surgeon may wish to stabilize a wrist or forearm while adjusting retractors around an incision area of a hand or finger. Often critical decisions are made during the course of the surgical procedure that require alteration to the fixation apparatus.
Traditional retraction systems typically utilize mechanical fasteners to provide a rigid connection among components. Re-positioning the retractor may require additional equipment to change retractive or stabilizing forces. Additional tools may also be required to assemble or to disassemble equipment. This presents problems because it is difficult to add or change equipment in an operating room without compromising the sterile environment. As a result, surgical procedures can be delayed while additional sterile equipment is introduced to the operating facility.
(b) Fixation
A variety of needs also arise in connection with surgery to fix the position of structures, such as surgical instruments, drapes, or a portion of a patient""s anatomy, some of which structures xe2x80x9cresistxe2x80x9d repositioning or maintenance of a selected position. These needs are conventionally addressed with adhesive, such as by use of adhesive tape, and by use of devices that mechanically connect or attach, such as clamps and retractors.
Another problematic shortcoming of existing fixation systems is their reliance on threaded or incremental adjusters. Threaded adjusters are frequently too slow for mid-procedure adjustment. Incremental adjusters are faster but often exert too little or too much retraction in detent positions.
Advances in surgical techniques have created the need for a fixation and retraction system that can be manipulated by the surgeon in the course of the procedure. This is often necessary to provide clear and varied views (visualization) of the incision site during the procedure. Traditional systems and practices require the presence of an assistant for the duration of the procedure to provide and adjust retraction. As a result, procedure errors can occur because of misunderstood verbal communication between the surgeon and the assistant. Thus, it is desirable for the surgeon to be able to manipulate the apparatus and is preferable that it be possible to do so with one hand.
(c) Drapes
Surgical drapes cover patients during surgery to maintain a sterile environment around the operative site. Traditional drapes consisted of cotton polyester blend textile similar to bedsheets. Users of this traditional fabric encounter problems of poor fluid transmission control and virtually no containment of fluids.
In a traditional drape fixation system, pincer style towel clips grasp a surgical drape and are secured to a patient or operating room structure with adhesive tape. To cover a patient with a surgical drape during a surgical procedure using the traditional fixation system, a user must lay a drape over the patient. Once in position, the user clasps a portion of the drape with the pincers of a towel clip. Pincers have pointed tips requiring care by users to avoid puncturing the drape. After grasping the drape, the user must secure the towel clip to a surface, such as an operating room table. Typically, adhesive tape is placed through a towel clip loop and affixed to a surface. In some situations, drapes must be clipped or sutured to the patient to provide fail-safe protection.
New drape fabrics have been developed, including one introduced by W. L. Gore using Goretex(trademark) fabric. Use of the Goretex(trademark) drape during a surgical procedure offers advantages found in outdoor clothing such as protection against wetness. However, new problems are associated with use of the Goretex(trademark) drape. Holes in the drape resulting from the pincer style towel clips destroy the desirable properties of the membrane. It is also undesirable to puncture such drape material with sutures.
In response to these problems, a new generation of drape clips have locking hemostats with large blunt surfaces to support the drape material. In addition, double faced tapes are available for securing drapes. However, double faced adhesive tapes lack the ability to adhere to the drapes effectively, particularly when attaching drapes to skin. This problem has led to somewhat extreme procedures such as scrubbing the patent to improve adhesion. Thus, current fastening methods are inefficient and unreliable, and a need exists for a method and system for securing a surgical drape to a skin surface without puncturing the surgical drape.
The above-described needs and problems, which are merely exemplary, demonstrate that a need exists for a surgical fixation and retraction system that provides stability while allowing efficient, sterile, relatively effortless adjustment of the system prior to or during a surgical procedure.
This system utilizes table-like ferromagnetic, typically metal, base components to which shielded magnet components attach in order to locate movable fixation and retraction components or other operating theater devices, such a surgical drapes. Ferromagnetic material conducts magnetic flux lines and is therefore is attracted to, and attracts, magnets. Use of small, powerful rare earth magnets permits system components to be attached quickly, easily and securely in an almost infinite number of configurations. Several different configurations of magnet-containing components are designed for direct contact with anatomical and other structures and for attachment to elastic and metal fixation and retraction components. Many of the magnet-containing components resemble chess pieces and are symmetrical about a longitudinal axis normal to the face of the magnet that attaches the component to a metal plate that serves as the base component. As a result, only location on the base plate matters, while rotational position relative to the base plate and other components does not matter. This simplifies assembly and adjustment of the components during use since rotational position generally does not need to be controlled. Fixation components in the form of such bodies of rotation are readily manufactured and are also well adapted for use with readily available disc-shaped rare earth magnets. These shapes also facilitate magnetic flux management, which is critical in theand operating theater environment where numerous ferromagnetic components and sensitive instrumentation may be present.
As is demonstrated in the detailed description of illustrative embodiments of the invention and some of the accompanying figures, this invention is readily usable for human hand surgery. It may also be used in a variety of other human and veterinary surgical procedures with appropriate adjustment of the scale of the components to match the requirements of the, human or animal anatomy involved.
The system is also usable for fixation of a surgical drape. One surgical drape fixation embodiment uses a metal cup and fixation tape to secure a surgical drape to a skin surface by attaching one magnet-containing structure to a skin surface with adhesive tape and trapping the drape between the magnet-containing structure and a second magnet or other component attracted by the magnet-containing structure. The metal cup includes a rim for coupling to the fixation tape, and the second side has a recess that receives one of the magnets. Two-sided adhesive tape bonds the cup to a skin surface or other surface. This embodiment gives medical personnel the ability to secure a surgical drape to the sterilized components of the fixation and retraction system while providing flexibility to adjust the position of the drape as needed. Securing a surgical drape with this invention protects a patient from fluid or other contaminants during a surgical procedure.
The fixation and retraction system of this invention reduces preparation and setup time, providing superior control and visualization and resulting in significantly reduced procedure times. The system provides a new level of direct control minimizing error from miscommunication between surgeon and assistant using powerful permanent rare-earth magnets. Force can be exerted and objects may be adjustably positioned during surgery using magnetic components, permitting a broad range of applications and component interoperability.
Use of rare-earth magnets in medical applications is challenging. The magnets must able to withstand autoclave temperatures and vigorous cleaning systems without power loss. Rare earth magnets contain iron, which requires corrosion protection. Normal magnet plating will not withstand repeated cleaning cycles, and encapsulation degrades magnetic performance. At the same time, the magnetic strength has to be harnessed in a manner that captures the bipolar power while controlling the magnetic flux field. The temperature, cleaning, corrosion and flux management problems can be solved by utilizing a magnetic alloy that is unaffected by temperatures up to 300xc2x0 Fahrenheit (150xc2x0 Celsius), and by creating thin wall stainless steel containers that hermetically seal the magnet and by fully shielding the magnets. At the same time, the system fixation components are designed to focus their magnetic strength on a single face, harnessing the maximum power of the magnets while simultaneously controlling the flux fields.
Unshielded magnets display a natural magnetic field consisting of a series of polar radiating loops of flux lines. In an unshielded state, magnets attract equally at their north and south poles. Once established on a metal plane, such an unshielded magnet provides both fixative force to the plate as well as radiating attractive force from the unobstructed pole, which is amplified from the natural state due to decrease in flux path losses. In a surgical environment, radiating magnet flux attracts all ferromagnetic materials, which can be undesirable. Flux management therefore can be an important feature of the system. Since a variety of ferromagnetic components are used during many surgical procedures, it is important that there are very high attractive forces between the components and the base plate and that the attractive force upward is minimized.
Shielded magnets allow for optimal utilization of the magnetic attractive forces and minimize the undesirable radiation of magnetic flux. For example, disk magnets have equal fields on each side of the disk. When a disk magnet is placed in a ferromagnetic cup, the cup magnifies the fixative force at the mouth of the cup by eliminating the air gap (air is a poor conductor of magnetic fields) and brings both poles of the magnet to grip on the plate surface. A secondary effect is substantial reduction of radiated magnetic flux. A magnet held in a ferromagnetic fixture provides an increase in fixation strength through field focus over a bare magnet while magnetic shielding is provided through a closed magnetic loop.
Autoclavable magnets include rare earth magnets such as the Somarium Cobalt (SmCo) types or formulations including neodymium, iron, and boron for coercivity retention at high temperatures like those in an autoclave. Other magnets that provide magnetic properties adequate for the application and that can be sterilized are also usable. Additionally, computer controlled laser welding permits the creation of thin wall stainless steel containers that hermetically seal the magnet, preventing corrosion without materially degrading the magnetic circuit performance.
One advantage of this surgical system is unrestricted motion, providing ease in positioning components. The magnetic fixators can be anchored anywhere on the surgical table, yet only two fingers are required for repositioning or fine tension control. The forces of magnetic attraction and tabletop friction are balanced to create an intuitively tactile holding system.
Surgeons often rely on the steady hand of a skilled assistant to follow their every move or command throughout a surgical procedure. This system reduces the surgeon""s dependency on a helping hand by providing control of fixation and retraction. The components often can be set, released, and manipulated with one or two fingers. An advantage to this system is that in many cases the surgeon can conduct the procedures without assistance, permitting some procedures to be carried out in a clinical setting under local anesthetic, rather than in a standard operating room.
Retraction applied by the surgeon is precisely maintained by the system. In a hand surgery embodiment, the system provides either static or dynamic forces up to about 800 grams. The 360xc2x0 radial retraction and slim retractor profiles improve visualization at the operative site. All of the components snap or slide together, allowing the surgeon to create and evolve fixation and retraction solutions as required throughout a procedure. The use of magnets provides properties not available with purely mechanical devices. The ability to move and leave a component under tension :using a contained but powerful built-in magnetic field avoids the use of locking or latching mechanisms common to purely mechanical systems. The system is not only faster, but also provides a far more sensitive adjustment range. The system uses strong rare-earth magnets built into component bases with a design that maximized fixative properties while effectively containing magnetic flux fields.
This fixation and retraction system stabilizes structures during surgery while allowing efficient, sterile adjustment of the system prior to or during a surgical procedure. The system may be used during various types of surgical procedures, including, but not limited to, hand, limb, digits, crania-facial, and veterinary surgery.
In one embodiment, this invention is a system for using a magnet in surgical fixation. In one form of this embodiment, the magnet forms part of a fixation component, which may also include a non-magnetic housing and a ferromagnetic cup. Another form of this embodiment includes a fixation component containing the magnet, and a ferromagnetic base plate to which the magnet attaches. In yet another form, the fixation component includes the magnet, a housing for the magnet, and a cleat attached to the housing.
Another embodiment of the invention is a device for repositionably securing a structure in a desired position during surgery, which device contains a magnet. One form of this embodiment can include a fixation component, a coupling component, a silicone rubber tube and a ferromagnetic base plate.
Yet another embodiment of this invention is a method for stabilizing or retracting an anatomical member during surgery that involves coupling a magnet to the anatomical member and attaching the magnet to a ferromagnetic base plate.
Accordingly, one feature of this invention is a surgical fixation and retraction system using magnetic components.
A further feature of this invention is a fixation and retraction system that allows good visibility of the operative site.
Another feature of this invention is a fixation and retraction system that provides a rigid connection and that has components that are part of a system and that are compatible with all other system elements.
An additional feature of this invention is that the components of the system disassemble for easy sterilization or disposal. Further, components do not degrade during aggressive sterilization methods.
Another feature of this invention is support on multiple planes. The system of this invention provides a broad range of retractive or stabilizing forces.
Another feature of this invention is very precise stabilization without backlash. Multiple components combine in series to increase range or in parallel to increase strength.
An additional feature of this invention is that no tools are required to set up or disassemble the surgical fixation and retraction system.
Another feature of this invention is to provide an invention that adapts to include non-system components.
Another feature of this invention is management of the collective magnetic forces generated by the system so as not to create undesirable magnetic attraction.
A feature of this invention is a surgical fixation and retraction system using magnets to hold through drape material without puncturing the membrane of the material.
An additional feature of this invention is a surgical fixation and retraction system with system components that operate through sterile drapes or plastic film without damage and provide isolation from other medical apparatus while maintaining stabilization.
Another feature of this invention is a method and system for attaching a surgical drape to a skin surface.
These and other features of this invention will be readily understood by those skilled in the art by reference to the following descriptions of the invention and the accompanying drawings.